private void OnPopupLoaded(object sender, RoutedEventArgs e) {
if (m_alreadyLoaded)
return;
m_alreadyLoaded = true;
if (Child != null) {
Child.AddHandler(PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(OnChildPreviewMouseLeftButtonDown), true);
}
m_parentWindow = Window.GetWindow(this);
if (m_parentWindow == null)
return;
m_parentWindow.Activated += OnParentWindowActivated;
m_parentWindow.Deactivated += OnParentWindowDeactivated;
}